package com.exam.online.system.util;

import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class CreateSimpleExcelToDisk
{
    /**
     * @功能：手工构建一个简单格式的Excel
     */
    private static List<Student> getStudent() throws Exception
    {
        List<Student> list = new ArrayList<Student>();
        SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd");

        Student user1 = new Student(1, "张三", 16, df.parse("1997-03-12"));
        Student user2 = new Student(2, "李四", 17, df.parse("1996-08-12"));
        Student user3 = new Student(3, "王五", 26, df.parse("1985-11-12"));
        list.add(user1);
        list.add(user2);
        list.add(user3);

        return list;
    }

    @SuppressWarnings("deprecation")
    public static void main(String[] args) throws Exception
    {
        // 第一步，创建一个webbook，对应一个Excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = wb.createSheet("学生表一");
        // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
        HSSFCellStyle headStyle = wb.createCellStyle();
        HSSFFont f  = wb.createFont();
        f.setFontHeightInPoints((short) 11);// 字号
//        f.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        f.setBold(true);// 加粗
        headStyle.setFont(f);
//        headStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
//        headStyle.setBorderBottom((short) 1);
//        headStyle.setBorderRight((short) 1);
        headStyle.setFillBackgroundColor((short) 20);
        HSSFRow row = sheet.createRow((int) 0);
        // 第四步，创建单元格，并设置值表头 设置表头居中
        HSSFCellStyle style = wb.createCellStyle();
//        style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
//        style.setBorderBottom((short) 1);
//        style.setBorderRight((short) 1);
        String[] header = new String[]{"学号","姓名","年龄","生日"};
        HSSFCell cell = null;
        for(int i=0;i<header.length;i++){
            cell = row.createCell((short) i);
            cell.setCellValue(header[i]);
            cell.setCellStyle(headStyle);
            sheet.setColumnWidth(i, 5000);
        }
        // 第五步，写入实体数据 实际应用中这些数据从数据库得到，
        List<Student> list = CreateSimpleExcelToDisk.getStudent();
        for (int i = 0; i < list.size(); i++)
        {
            row = sheet.createRow((int) i + 1);
            Student stu = (Student) list.get(i);
            // 第四步，创建单元格，并设置值
            cell = row.createCell((short) 0);
            cell.setCellValue(stu.getId());
            cell.setCellStyle(style);
            cell = row.createCell((short) 1);
            cell.setCellValue(stu.getName());
            cell.setCellStyle(style);
            cell = row.createCell((short) 2);
            cell.setCellValue(stu.getAge());
            cell.setCellStyle(style);
            cell = row.createCell((short) 3);
            cell.setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(stu.getBirth()));
            cell.setCellStyle(style);
        }
        // 第六步，将文件存到指定位置
        try
        {
            FileOutputStream fout = new FileOutputStream("D:/students.xls");
            wb.write(fout);
            fout.close();
            System.out.println("输出成功！");
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
}
